1. Field of Invention
The present invention relates to an inflatable sportsball, and more particularly to an inflatable sportsball having a cushioned carcass by constructing a cushion layer therein so as to increase the softness of the sportsball and enhancing the roundness of the sportsball.
2. Description of Related Arts
Sportsballs, such as basketballs, soccer balls, and footballs conventionally comprise an inflatable bladder and a cover. The inflatable bladder is disposed within the ball cover for propping up the ball after inflation. The inflatable bladder can be made of rubber or polyurethane that can be reinforced with windings of nylon thread or polyester thread. The ball cover generally comprises a carcass and panels made of rubber, synthetic leather or leather, wherein adjacent panels are separated by rubber channels.
In order to improve a player""s ability of gripping the sportsball and to reduce the shock of impact, the carcass of the sportsball is made to include cushion layers, such as panels of sponge rubber, which are directly adhered on the carcass between the rubber channels. However, the cover panels which cover the cushion layers do not adhere well to the cushion layers. The cover panels also have a tendency to peel away from the additional cushion layers.
U.S. Pat. No. 5,636,835 suggests that after the winding thread layer is attached to the bladder, panels of foamable rubber layer are attached to the winding thread layer. The foamable rubber layers are made from a type of rubber designed to foam and create cellular sponge rubber upon application of heat. Consequently, the foamable rubber layers stick directly on the winding thread layer and hold their positions prior to placement in a mold. Then, seam channels of unformed seam material are placed over the discontinuities between individual panels of foamable rubber layer, i.e. a rubber layer containing foaming agent.
After the foamable rubber layers and unformed seam channels are in position, the entire arrangement is placed into a carcass-forming mold. In the mold, the carcass is cured under heat in the same way of the conventional ball carcass. The heat causes the foaming agent within the foamable rubber to expand and the panels of foamable rubber layer forms a single, uniform cellular sponge layer. The thickness of which is dependent on the space between the outer diameter of the winding thread layer and the inner diameter of the mold and the amount of the out gate created by the foaming agent. The seam channels are molded at the same time, thereby creating the raised seams familiar to conventional basketballs. The sponge layer, which is substantially and directly surrounding the layer of winding, directly underlies the raised seams. The inner carcass portion, cellular sponge layer and raised seams together define the ball carcass.
U.S. Pat. No. 5,681,233 suggests that the bladder is inflated and placed in a vulcanizing or curing mold where the bladder is cured by heating. After curing, the inflated bladder is wound with reinforcing thread. Flat sheets or panels of sponge rubber are laid on the wound bladder. The panels of sponge rubber are arranged so that a gap of about 5 mm separates adjacent panels to form a carcass. The carcass is placed in a spherical mold, and the inflated carcass is heat molded at 160xc2x0 C. During the molding process, a foaming agent in the sponge rubber foams and creates a cellular structure in the foam rubber, which also bonds to the wound bladder, so as to form the ball carcass.
In view of the above conventional arts, a special type of foamable rubber, which is designed to foam, is used to directly stick on the winding thread layer of the inner carcass, wherein such foamable rubber reacts to create the cellular sponge rubber upon application of heat within a kind of close type mold. Therefore, the conventional cushioned inflatable ball generally comprises an inflatable bladder and a layer of winding covering the bladder to form an inner carcass defining the shape of the ball, a cellular sponge rubber layer surrounding the inner carcass, and a cover layer surrounding the sponge rubber layer. The cellular sponge rubber layer is formed upon the application of heat within a close type mold, wherein the foamable rubber releases gas upon application of heat to produce a plurality of air meshes and increase the thickness of the rubber to form the cellular sponge rubber so as to achieve the softness feel and effect.
However, there are some drawbacks of the conventional cushioned inflatable balls. Since the foaming process of the sponge rubber is processed in a closed state, that is the foamable rubber is heated inside the press mold in an air tight manner, the gas released from the foamable rubber has no where to escape and no way to be evenly distributed during foaming between the interior surface of the mold and the inner carcass. In other words, it is very difficult to obtain a cellular sponge rubber layer with even thickness. Moreover, the released gas will inwardly press against the inner carcass and force the winding thread to separate from the inflatable blabber, that may affect the roundness of the inflatable ball.
According to both U.S. Pat. Nos. 5,636,835 and 5,681,233, the foaming reaction of the foamable rubber within the close type mold cannot be completely controlled such that the sponge rubber after reaction may not have a uniform thickness, which may affect the softness and the stiffness of the ball. Practically, the conventional cushioned carcass structure provides a great headache to most of the ball manufacturers, that is why a large number of manufactured balls will fail the quality test and become defective goods. It not only increases the manufacturing cost unreasonably but also adversely affects the softness and gripping feel of the balls.
Furthermore, in the U.S. Pat. No. 5,636,835, the thickness of the raised channels is reduced by the underlying uniform cellular sponge layer, so that the raised channels are easier worn out that shortens the life span of the ball.
Also, in order to fit different types of playground and different ages of players, different types of sportsball with different levels of softness and stiffness must be made. For example, the sportsball for junior players may have softer ball carcass and the sportsball for professional players may have stiffer ball carcass.
A main object of the present invention is to provide an inflatable sportsball which is integrally constructed with a plurality of cushioned portions between the seam channels so as to provide uniform cushion softness for the sportsball.
Another object of the present invention is to provide an inflatable sportsball with cushion layer, which has a softer feeling to reduce the painful during ball passing and catching, especially suitable for children, training players and amateur players.
Another object of the present invention is to provide an inflatable sportsball with cushion layer which can reduce the impact force between the player and the sportsball, so as to prevent an unwanted injure of the player hit by the impact force while receiving the sportsball. Thus, the cushion layer tolerates more impact on the sportsball so as to retain the shape of the sportsball.
Another object of the present invention is to provide a method of manufacturing an inflatable sportsball, which can manufacture a cushioned sportsball in an efficient and economic way and effectively control the softness and roundness of the sportsball.
Another object of the present invention is to provide a method of manufacturing an inflatable sportsball with cushion layer, which can adjust the softness of the sportsball easily. Also, the manufacturing method enables the cushion layers of the sportsball made having a uniform thickness so as to enhance the roundness of the sportsball.
Accordingly, in order to accomplish the above objects, the present invention provides an inflatable sportsball which comprises:
an inflatable ball carcass defining a shape of the sportsball, wherein the ball carcass is an integral hollow ball body, which includes an inner inflatable rubber bladder, a winding thread layer that surrounds the rubber bladder with a reinforcing thread, an outer rubber layer surrounding the winding thread layer in such a manner that the outer rubber layer, the winding thread layer and the rubber bladder are integrally fused into a single fusion layer, wherein the ball carcass further includes a plurality of seam channels integrally and spacedly raised from an outer surface thereof and panels of foaming layer which are positioned between the seam channels and sandwiched between the outer rubber layer and the inner rubber layer fused on top of the winding thread layer; and
a ball cover for covering the ball carcass, wherein the ball cover comprises a plurality of skin panels attached to the outer surface of the ball carcass between the seam channels.